Vehicles for carrying cargo and for loading cargo into vehicles, such as aircraft and the like, are generally known. Such vehicles typically have a platform that may be raised upward to position the platform at a loading portion of the vehicle or aircraft to ease loading of the cargo from the vehicle to the aircraft. The vehicles may be able to adjust the platform to maintain the platform relatively level at the raised position to support the cargo at the desired level at the aircraft or loading/unloading area. Typically, such vehicles have the cargo lifted upward from the ground and placed on the platform at the vehicle prior to transporting the cargo, and then elevate the platform to the desired height at the targeted vehicle or aircraft. Examples of such vehicles are shown in U.S. Pat. Nos. 3,666,127; 3,688,926; 3,944,096; 5,165,838; 5,630,694 and 6,447,044. Such vehicles often include multiple pivotable arms/linkages which pivot relative to one another and to the frame and platform of the vehicle in order to provide the desired elevational adjustments to the vehicle. Also, although such vehicles are often capable of transporting and elevating cargo to a desired elevated loading area, such as at an aircraft or the like, the cargo or articles must first be lifted upward onto the vehicle platform, which is often cumbersome and difficult to accomplish, and sometimes requires a forklift or the like.
Such known vehicles often allow for adjustment of the height of a deck of the vehicle relative to the ground and include a frame or deck supported by wheels and axles, with the axles including a suspension system for absorbing the impact of the tires with the ground as the vehicle travels over uneven terrain. The ground clearance of such vehicles is limited by the size of the wheels and tires.
Some vehicles provide for adjustment of the height of the deck relative to the axles and ground, and include an adjustment system, such as a hydraulic lift system that raises the deck relative to the axles. The hydraulic system may raise and adjust the deck relative to the ground, such as in the manner described in U.S. Pat. Nos. 3,743,044 and 5,110,153, which are hereby incorporated herein by reference. Such systems are complicated adjustment or elevating systems and do not allow for adjustment of the ground clearance of the trailer or vehicle or allow for the vehicle to travel over uneven terrain.
Therefore, there is a need in the art for an improved trailer or vehicle for carrying cargo and for loading and unloading cargo at platforms or areas of different heights that overcomes the shortcomings of the prior art.